Maybe it needs help with pollination? I've no experience with cape gooseberry, but I know tomatoes and peppers (which are related to cape gooseberry) can be pollinated by tapping and shaking the flower stem. Other kinds of flowers can be pollinated by transferring the pollen from anthers of one flower to pistils of another with a soft watercolor brush (or clean makeup brush). Cotton swabs will work for larger flowers like squash.

I've been doing that with an indoor lemon tree (small cutting grown plant at this point, actually -- hardly a "tree" ) which has been flowering since it was brought inside for the winter.

agreed w/ lorax...while i don't have direct experience with these, I'm planning on growing them and reading up - some authors suggest that they will hardly bear at all with 'adequate' water and nutrients - that they're one of those plants that 'thrive on neglect'...some went so far as to say that they only bear well in 'extremely poor soil'.